Answer:
One explicit incident when Zeus was overthrown was when for some nebulous reason, the other Olympians got sick of Zeus being in charge, so while he was napping they bound him up in chains. The rebellion was spearheaded by Hera, Athena, and Poseidon (some versions swap one of them out with Apollo), who proceeded to argue which of them should be the sole person in charge, i.e. replace Zeus. While they argued, the Oceanid Thetis (later the mother of Achilles) got Briareus, one of the Hundred Handed Ones whom Zeus rescued from Tartarus during the Titanomachy, to free Zeus. The rebels quickly bowed back down to Zeus after that.
Step-by-step explanation: